1. Field of the Invention
The present invention relates to the field of fiber-optic technology and, more specifically, to an optical plug-in connection.
2. Description of the Related Art
In fiber-optic communications technology, use has long been made of optical plug-in connector systems in which two optical fibers are coupled to each other by two plug-in connectors, in each of which one of the fibers ends in a ferrule, being inserted from opposite sides into a coupling or an adapter in such a way that the ferrules slide from both sides into a guiding sleeve arranged in the coupling and butt with the end faces against each other. Plug-in connector systems of this type are known and marketed under the designation SC, LC, E-2000 (LSH) or LX.5.
In the known plug-in connections, use is usually made of locking devices by which the plug-in connector is locked when it is inserted into the coupling, so that it can only be pulled out of the coupling again after unlocking. In the case of a plug-in connection of the type E-2000 (LSH), as substantially described in EP-B1-0 570 652 cited at the beginning, a locking tongue is formed in the coupling and has a hook formed on its end as a locking element. When the plug-in connector is inserted, this hook locks in at an undercut in the plug-in connector and in this way holds the plug-in connector in the coupling. This locking can be released by the locking tongue being raised by a tilting lever which is arranged on the plug-in connector and can be operated from the outside.
In the case of a plug-in connection of the type LX.5, as substantially described in U.S. Pat. No. 5,883,995 cited at the beginning, a locking arm with an upwardly angled-away, hook-shaped locking element is formed on the plug-in connector itself. When the plug-in connector is inserted into the coupling, the locking element locks in at an undercut arranged on the upper side of the coupling and can be unlocked again by the locking arm being pressed downward in a portion located outside the coupling. A similar principle with a locking lever pivotably mounted on the plug-in connector is also realized in EP-A1-1 072 917 cited at the beginning.
In the case of the known plug-in connection systems described above, the locking mechanisms are formed in such a way that they can easily be unlocked by pressing a lever or the locking arm itself. This can easily also lead to unintentional disengagement of the locking and ultimately unintentional disconnection of the plug-in connector. This not only has the consequence that the fiber-optic connection is unwantedly interrupted at this point, but also leads to safety problems, because laser radiation of a hazardous intensity can possibly escape from the interrupted connection.
It is therefore desirable to have optical plug-in connections which do not exhibit the aforementioned disadvantages.